1. Field of the Invention
The invention relates to a tool utilized in reloading spent cartridge cases and in particular it relates to a piloted finishing tool for deburring and chamfering an edge of the primer receiving aperture in a cartridge case, known as the flash hole.
2. Background of the Invention
The reloading of spent cartridge cases is a finely developed art. The reloading operation is typically accomplished with a reloading press and related tooling to perform the many operations required. Basic operations necessary to accomplish the reloading of spent cartridge cases include; removal of the spent primer, inserting and seating a new primer, resizing the cartridge case, charging the case with powder, and seating a bullet in the case.
As stated, the above is but basic to a reloading operation. Many individuals who reload their own ammunition, especially those involved in competitive shooting meets, go beyond the basics to obtain the utmost in consistency from shell to shell in the reloaded ammunition. The uniform ignition of the powder charge is one area that is of concern.
During the original manufacture of the cartridge case, the flash hole in the base of the cartridge often is produced by a punching operation. The punch tends to leave a burr of upstanding material at the periphery of the flash hole within the cartridge. This burr tends to shield the powder surrounding the flash hole and thus will affect the ignition of the powder by the primer when a weapon is fired.
To insure uniformity and consistency in the ignition of the powder, the serious reloader removes the burr. Additionally, the edge of the flash hole is slightly chamfered, which provides a "funnel" (i.e., a frusto-conical section) that aids in the even ignition of the powder by the primer.
The burr removal and chamfering operation was accomplished by using a tool that was insertable into the cavity of the cartridge case. The tool had a cutter section mounted on its end and generally had an end guide that was inserted into the flash hole to steady the tool during the cut. This tool lacked in features that would provide the desired end results for the user. The tool did not have a suitable centering guide. It was very difficult to obtain a chamfer that was axially aligned with the flash hole and it did not have a positive stop to limit the depth of cut of the cutter. An additional frustration was that a user had to "hunt and peck" with the end of the tool to position the end guide in the flash hole.
U.S. Pat. No. 4,807,511 issued to Markle discloses a hand held tool for deburring and chamfering the flash hole that has a depth stop and a conical guide. The depth stop of the tool however, is placed adjacent the cutter, and the burrs removed from the flash hole may stay between the stop and the bottom of the cartridge resulting in an inaccurate depth control. Also, the conical centering device centers the center piece of the tool relative to the neck of the cartridge, but it does not positively guide the cutting portion of the tool into the flash hole.